HOWTO-Booting with Yaboot on PowerPC
Chapter 10 - Yaboot as a Temporary Bootloader

It's very convenient for certain tasks like installing a new system the first time without a CD, or rescuing an existing system, to boot a ramdisk system such as an installer directly from files placed on an existing partition.

An example is the Debian installer. It is contained in a floppy-image root.bin file which yaboot can boot directly. A simple yaboot.conf to initialize the ramdisk, yaboot, root.bin, and a kernel image (named linux in this example) are all that is needed. All files are placed at the root level on an existing partition.

The yaboot.conf file for this purpose contains just four lines:

         image=linux
         label=install
         initrd=root.bin
         initrd-size=8192

If you create yaboot.conf in the MacOS, you must convert it to use Unix newlines (linefeeds only). If you use MacOS newlines (just carriage returns), yaboot will be unable to read the file.

You must pick a partition that is formatted with either HFS or HFS+. If you have Mac OS X installed on a UFS partition (You can use the OS X "Disk Utility" app to check this), you will have to find another partition to use. If Mac OS X is installed on UFS, you probably have one or two partitions of the "Apple_Boot" type. They have HFS filesystems on them. Pick one, mount it under MacOS X, and store the files there.

Boot into OpenFirmware, and type at the prompt:

         0 > boot hd:xx,yaboot

replacing xx with the partition number of the partition where the kernel and yaboot files were placed, followed by a return. At the boot: prompt, type install followed by a return.

HOWTO-Booting with Yaboot on PowerPC